Blast furnace construction



Sept. 17, 1940. w CLARK 2,215,368.

BLAST FURNACE CONSTRUCTION Filed March 24, 1959 I I FOO "Y 53' 4. 2 N INVENTOR 3d 50 53 WgburT. Clark, HAM; M W

ATTORNEY Patented Sept. 17, 1940 UNITED STATES BLAST FURNACE CONSTRUCTION Wilbur T. Clark, Lakewood, Ohio, assignor of one-half to Richard'W. Treverton, Buffalo, N. Y.

Application March 24, 1939,1Serial No. 263,951

8 Claims.

The present invention relates to blast furnace construction and has particular reference to an improved means for separating solid material from the gas discharged from the furnace, and

for re-entering such solid material into the furnace.

In the conventional blast furnace construction, furnace gases are taken from the top of the furnace chamber and carried by downcomers todust catchers, wherein solid material carried'by the gas stream is separated from the gaS. Such material, which may vary in size from large pieces to very finely divided particles, may then be transported to a sintering plant to be fused into larger units, after which it may be re-entered into the blast furnace in the usual manner in which the furnace charge is entered.

According to the present invention means for separating solid material from the furnace gas are disposed above the furnace, and the solids recovered are passed, preferably by gravity, into the charging hopper of the furnace.

Means 'are provided whereby the passage of such material into the charging hopper may be I effected at times when the small bell is closed, thereby preventing escape of gas and dust from the dust catchers through the gas seal and small bell opening. Upon filling of the hopper by dropping of the small bell, the returned material is entrapped, and thereafter, upon opening of the large bell, is carried into the furnace chamber with the charge. In this way small particles returned to the furnace chamber may be retained therein, whereas if they were returned directly into the furnace they would be swept immediately into the gas uptakes due tothe high gas velocities maintaining in the upper portion of the furnace.

These and other objects and avantages of the present invention will become apparent from the following description of the embodiment of the invention indicated in the accompanying drawing, wherein:

Fig. 1 is a front elevation showing the upper portion of a blast furnace provided with the improved separator and return means;

Fig. 2 is a side elevational view thereof; and,

Fig. 3 is a sectional view taken along line 33 of Fig. 1.

As shown in the drawing, the upper portion of the blast furnace ll may be of usual form, having above the furnace chamber l2 thereof a charging hopper I3 normally closed by a large bell l4, and above hopper l3 2. small hopper I5 closed by a small bell [6. A gas seal 29 prevents escape of gas from the furnace when the large bell is open and supports the small bell hopper I5. Any suitable means, not shown, may be provided to raise and lower the bells whereby the furnace may be charged by opening the small bell to empty the charge from small hopper l5 into the furnace charging hopper [3 while the large bell is closed, and then, while the small bell is closed, dropping the large bell to admit the charge into the chamber 12.

Extending upwardlyfrom the furnace chamber are the usual uptakes l'l through which furnace gases are passed to the conventional downcomers l8. During operation the high velocity of gases passing upwardly through the furnace chamber and through uptakes I1 causes particles of the charge, ranging in size from very finely divided material to relatively large pieces, .to be swept from the furnace chamber in the gas stream.

In order to recover and return a large portion of this solid material to the furnace, the present invention provides one or more gas cleaners or separators l9 between uptakes I! and the downcomers 18, for separating solid material from the gas stream, and conduits 2| extending from the cleaners to the charging hopper 53 for returning the recovered material.

The cleaners l9 may be of any suitable type. In the illustrated embodiment each unit 19 has a cylindrical housing 22 into-which a pair of uptakes I! open as indicated at 23 on opposite sides, and substantially tangentially, to impart a swirling motion to gases entering the housing. A riser. 2i opens into the interior of each housing below the inlet openings 23, and terminates at its upper end in a bleeder valve 26. One of the downcomers l8 joins each riser 24 above the housing 22, the juncture being indicated at 25.

The swirling furnace gases passing downwardly in housing 22, and thence upwardly through riser 24, precipitate solid material to the funnel shaped bottom of the housing, from where the material may pass by gravity through the conduits 2! which extend to the large bell chamber, or charging chamber, 13. Valves 2? are provided to control such passage of the recovered solids.

In operation the valves 21 may be normally open to allow passage of solid material from housings 22 but will be closed when the small bell I6 is opened for admitting a charge into chamber l3, or prior to such opening. In either case, the material returned through conduits 2|, much of which may consist of particles of very small size, will be entrapped in the furnace charge, and Will be carried therewith into the furnace chamber I2 upon subsequent opening of the large bell M. In this way much of the returned material is prevented from being immediately swept again into the uptakes l! by passing furnace gases.

From the foregoing it will be apparent that the valves 21 may be operated by any suitable means. If desired they may be closed simultaneously with opening of the small bell [5 by having their control levers 28 connected to a cable joining the small bell operating means, or if preferred, they may be operated independently of the small bell. be closed when the small bell I6 is open in order to prevent furnace gases fromescaping through small bell hopper to the air.

It will be understood that the structure shown and described herein is merely illustrative of the inventive principle involved, and that these may be otherwise embodied without departing from the spirit or scope of my invention.

I claim:

1. In a blast furnace having a furnace chamber with a gas uptake from the top thereof, a charging hopper above said furnace chamber with a small bell for controlling entrance of a charge thereinto and a large bell for controlling passage of said charge therefrom into the furnace chamber, a separator associated with said gas uptake for separating solid material from the gas, a conduit for passing such solid material from the separator into the charging chamber, and valve means associated with said conduit for the controlling passage of material therethrough, whereby such passage may be effected at times when said small bell is in closed position.

2. In a blast furnace having a furnace chamber, a charging hopper thereabove with a small bell for controlling entrance of a charge thereinto and a large bell for controlling the movement of the charge from said hopper into the furnace chamber, means for conducting gas from the furnace chamber and means associated therewith for separating solid material from the gas, and means for conducting such solid material into said hopper, said means including a valve whereby such solid material may be entered into said hopper at times when said small bell is closed.

3. In a blast furnace having a furnace chamber, a charging hopper thereabove with a small bell for controlling entrance of a charge thereinto and a large bell for controlling the movement of the charge from said hopper into the furnace chamber, means for conducting gas from the furnace chamber and means associated therewith for separating solid material from the gas,

However, the valves 21 should and valved passage means for passing such solid material into said hopper.

4. In a blast furnace having a charging hopper provided with a valve for admitting a charge into said hopper, and the furnace having a gas uptake, a cylindrical housing above the charging hopper, said gas uptake opening into the housing substantially tangentially thereof, a gas outlet pipe extending from said housing and having its inlet end in said housing below the opening of said gas uptake, and a conduit extending from the bottom of said housing into said charging hopper.

5. In a'blast furnace having a charging hopper provided with a valve for admitting a charge inot said hopper, and the furnace having a gas uptake, a cylindrical housing above the charging hopper, said gas uptake opening into the housing substantially tangentially thereof, a gas outlet pipe extending from said housing, and a conduit extending from the bottom of said housing into said charging hopper.

6. In a blast furnace having a furnace chamber and a charging hopper thereabove provided with a valve for admitting a charge into said hopper, a substantially cylindrical housing above,

said hopper, a gas uptake from said furnace chamber opening into said housing substantially to such passage.

'7. In a blast furnace having a charging hopper provided with a valve for admitting a charge;

into said hopper, and the furnace having a gas uptake, a separator associated with the gas up:

take for separating solid material from the gas,

means for passing such solid material from the separator into said hopper, and valve means associated with the last mentioned means for controlling the passage of such solid material into,

said hopper.

8. In a blast furnace having a furnace chamber, a charging hopper thereabove with a small bell for controlling entrance of a charge-therainto and a large bell for controlling movement" of the charge from said hopper into the furnace chamber, means for conducting gas from the furnace chamber including means for separating, solid material from the gas, and a-conduit forpassing such solid material into said hopper, said conduit having associated therewith means whereby the conduit may be closed small bell is open.

WILBUR TQCLARK.

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